Dynamic Hydraulic Column Activation Method

Abstract

Disclosed is a method and apparatus for promoting chemical reactions in a hydraulic column, preferably in the form of a well, provided with an outer casing, an inner liner within and spaced from the casing, and a steam line within and spaced from the inner liner. A downwardly flowing column of a material to be treated is introduced between the casing and the liner and is heated at the bottom and caused to undergo chemical changes due to the high pressure and temperature conditions. The reaction zone located generally at the bottom of the well is maintained free of extraneous oxygen, that is, free of oxygen except that which might be inherently entrained in the fluid material. The heated material is forced upwardly between the liner and the steam line solely by the column pressure and may be continuously removed at the top, thus providing a continuous process. If the material being treated is sewage, it may be provided to the column in its raw state, that is, not being concentrated or fortified by refuse or other combustible materials.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of my copending application Ser. No. 735,066 filed on June 6, 1968, now abandoned.

Description

BACKGROUND OF THE INVENTION

It is well-known that an increase in the speed and efficiency of many chemical reactions can be induced by subjecting the substances involved to greatly increased pressure and temperature conditions. A common example of this would be the household "pressure cooker" wherein the chemical reactions involved in cooking are accelerated by use of induced pressure. It has also been found that the utilization of pressure not only causes substantial yeilds from processes which could not practically be effected under atmospheric conditions, but also often eliminates or by-passes undesirable intermediate by-products which would tend to hamper the primary reaction objective.

In utilizing the advantageous effects of high pressure on certain chemical reactions, various ways of attaining the high pressure have been attempted, such as utilizing a batch-type vessel to confine the materials which expanded due to the addition of heat, generally giving off vapors which pressurized the container. This batch-type reactor was and is deficient in many respects. First, and most basically, a sufficiently sealed container was not economically produced. Often the walls of the container tend to ablate at the seams or otherwise give way to the high pressure. Further, the batch-type heat expansion system is inefficient in that little if any of the energy utilized to heat the materials is recovered.

The obvious response to the problem was the use of a pipe-type batch reactor or autoclave having a simple closure. However, this system was complicated with respect to vessel charging and discharging, there being no practical way of placing the material to be treated in the pipe, and likewise extracting it upon completion of the batch process.

Paralleling the development of the heat-expansion batch-type vessel, was the utilization of a pump to effect the pressures otherwise effected by the above-described heating arrangement. The pump system had its advantages in that it could also be utilized to create a more continuous process, as opposed to the batch concept. However, the pumping method was limited as it is today, to moving the fluid materials of a consistent nature; that is, the pump cannot economically or efficiently handle abrasive materials, or many other materials in liquid suspension. Also inherent in the pumping system is the fact that leakage, erosion, corrosion and cavitation of the pumps themselves make their use quite limited.

Recently, batch-type reactors have been partially improved through the development of better sealed, quick opening doors, but remain limited in pressure and temperature range as well as volume output. Additional work has been done with continuous-feed reactors, but these remain inefficient in percentage of yield as well as frequently requiring costly separation devices. Further, the recent availability of better pump seals has improved pump applications to a degree. However, pumps still prove impractical in handling large volumes of variable density, sometimes abrasive fluids with process materials in suspension.

One of the applications of high pressure techniques is found in the treatment of sewage. Since raw sewage can contain most any known chemical compound, and does contain much objectionable matter which can best be treated under the aforementioned high pressure principles, its discussion herein is best used as a representative example.

Present sewage treatment involves the initial process of separation by settling of the solid into some type of basin for further treatment. Many objectionable constituents of sewage defy separation by this method and in many instances are simply aerated, or diluted and discharged into natural waters. This handling technique is normally ineffective in the destruction of appreciable percentages of the spores of pathogenic bacteria.

The settled solids are concentrated and processed by various methods, some using high pressure autoclave type techniques. Presently known methods include digestion, flocculation and filtration, direct burial, incineration, air drying, wet combustion, centrifugal separation, lagooning, activated sludge with recirculation, and others. All of these methods, however, have the basic disadvantage of being directed only to a relatively small percentage of the total sewage influent. As alluded to above, matter in solution, matter in colloidal dispersion, or matter which by virtue of its specific gravity is unsettleable simple never reaches the treating mechanism. These categories include living organisms, fatty acids, protein, cellulose, carbohydrates, and the volatile hydrocarbons representative of the aforementioned materials in various stages of decomposition, as well as precipitated detergent end products, rubber and polyethylene materials.

Despite the intense use of various systems presently practiced, these objectional materials persist in accumulation about the human environment. The abrasive and unpredictable variable nature of sewage has made large scale high pressure pumping impractical. Batch autoclaves and vessel reactors are limited in capacity, and function only for laboratory sterilization and small specialized treatment situations.

For example, one proposed but not presently commercially acceptable method of treating waste materials is a wet combustion process described in U.S. Pat. No. 3,449,247 wherein concentrated sewage is augmented by the addition of combustion material and provided to a vertical hydraulic column. Then, utilizing the combustible material as fuel, oxygen or air is added to the material so that the wet combustion process may take place. The air further provides an air lift so that the treated material will rise to the top of a separate vertical column.

Such a process is, however, limited to high concentrations of organic material in water. After the wet combustion process has taken place, the end products are useless and are discarded. Further, many materials exist in a natural state far too dilute for practical use in such a process and would require extreme concentrations or additions of organic material to effect wet combustion. Working with such concentrations, however, is intolerable when contemplating a continuous process in a vertical hydraulic column. The friction losses of these highly viscous materials result in pressure differentials being such as to cause collapse of the piping network handling the material.

Further, when the vertical reactor is put into the ground, installations under this patent would have no means to prevent escape of process fluids to the surrounding strata or means to prevent contamination of the process fluids by decomposing the exposed strata.

Other complications of the method described in U.S. Pat. No. 3,449,247 include multiple deep well drilling; formation of underground chambers for the storage of air; high residual effluent pressures; the necessity of preheating the material to begin combustion; limitations of materials of construction due to exposure to high temperature combustion; odor control; no means to recycle the fluid limiting the process to once through applications; no means to reverse the flow of the fluid; no means to mechanically mix the materials under peak reactor conditions; no means to maintain heat transfer effectiveness under low flow conditions; no means to deter adherence of materials to the piping apparatus; and no means to introduce energy into the process without oxidizing materails in suspension or solution.

The treatment of sewage is much like the purification of water to make it potable; with the latter, the objectionable matter is vastly diluted. Nevertheless, the system of U.S. Pat. No. 3,449,247 and present techniques with respect to water treatments still leave the problems of rag and leaf exclusion, grit removal, solids concentration, organic digestion, solids and waste comutation, limited design flow range, exposure to the atmosphere, escape of volitile contaminents, odor control, phosphate and soluble pollutant removals, excessive land use, aesthetic limitations, infectious virus transmission, thermal pollution, sensitivity of bacteriological treatment to industrial spills, dependage on manual labor for operation, necessity for extensive pipe line transmission or pumps to raise waste waters above surface waters for gravity flow through plant, frequent subjection to flooding, necessity for extensive intercepting collection systems due to inefficient operation in low flow ranges, infiltration of fresh and sea water in collection systems, in rush of fresh water from combined sewerage, and others, which problems remain unsolved.

One other chemical process, utilizing high temperatures and pressures is the devulcanization of rubber, which is mentioned by way of example. This has been accomplished to some degree in batch reactors with some attempts having been made at pumping the material through pipe reactors. Basically, discarded vulcanized rubber is ground up, kneaded, and mixed with a catalytic type substance such as zinc chloride or casutic soda. This material is then subjected to temperatures and pressures conducive to the acceleration of breaking the sulfer linking associated with vulcanization. However, it has been found that the same problems which plague the high pressure reactor art in general, also plague the process of devulcanization of rubber in such systems, the process being slow and limited in batch volume since pumping is generally prohibitive.

In short, almost any known material which could advantageously be treated in a high pressure reactor is also subject to the various shortcomings described above. Further, the teachings of U.S. Pat. No. 3,449,247 are severely limited to the wet combustion process which is inherently limited to the treatment of materials wherein it is advantageous to have oxygen present. Many chemical reactions, such as the devulcanization of rubber described above, will simply not satisfactorily occur if oxygen is present.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide a novel method to treat sewage waste material as found in the environment without the necessity of augmentation or concentration thereof with combustible refuse and the like.

It is an additional object of the present invention to provide a method, as above, which will treat sewage waste material and promote chemical reactions in other oxygendeficient materials without requiring the addition of oxygen, thereby precluding the disadvantageous effects of wet combustion.

It is a further object of the present invention to provide a method, as above, which does not require preheating of the influent material to be treated.

It is a still further object of the present invention to provide a method, as above, which utilizes a well-like structure to provide a vertical hydraulic column without being plagued by direct contact with the surrounding strata.

It is another object of the present invention to provide a novel method for treating material utilizing a hydraulic column reactor which will combine the continuous effect of the pump-type reactors.

It is another object of the present invention to provide a method, as above, which can handle large volumes of material while retaining much of the heat and pressure energy input as well as increasing yields of known processes.

It is still another object of the present invention to provide a method, as above, which eliminates the need for a pumping device, thus facilitating the manner of the charge and discharge thereof.

It is a further and more specific object of the present invention to provide a method, as above, adapted for the more efficient, more economic, and total treatment of sewage and the like.

It is a still further and more specific object of the present invention to provide a method, as above, adapted to accelerate chemical processes by use of high pressures and temperatures, such as the purification of water, devulcanization of rubber, etc.

These and other objects which will become apparent from the following specification are accomplished by means hereinafter described and claimed.

In general, the apparatus employed to promote the desired chemical reactions consists of a hydraulic column to provide the reaction-inducing high pressure, and a means to provide heat energy to the bottom of the hydraulic column. The preferred manner of obtaining the high pressure is by utilizing a deep well having casing to conduct the material downwardly and a liner spaced within the casing to return the material to the surface. A steam line or other heating means is spaced within the liner to supply the necessary heat energy at the bottom of the column.

Means are provided within the casing for the injection of a catalyst at any depth, should the process require it. At the bottom of the well, the material is directed from between the outer casing and the liner into the bottom of the liner. This area is heated by steam or another media and the desired chemical reactions are thus promoted or accelerated. Since no extraneous air, oxygen or combustible refuse is provided to the column, the disadvantageous effects of wet combustion can be avoided. The heated substance, being lighter than the denser and cooler influent, is caused to flow up within the liner. As the warm effluent passes by the cool influent, some of the heat is transferred through the liner from the effluent to warm the influent. Thus, not only is a continuous process assured, but also much of the heat energy supplied is conserved and passed on to the influent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a somewhat schematic elevational view of a preferred embodiment of the apparatus of the invention, parts being broken away and in section.

FIG. 2 is a top plan view thereof.

FIG. 3 is a schematic flow diagram of a preferred embodiment of the invention.

FIG. 4 is a graphic illustration of representative pressures and temperatures of a material as it is being treated.

FIG. 5 is an enlarged sectional view of the apparatus at the bottom of the hydraulic column according to a preferred embodiment of the present invention.

FIG. 6 is an enlarged view of the liner within the outer casing showing the liner stabilizer according to a preferred embodiment of the present invention.

FIG. 7 is a sectional view taken substantially along line 7--7 of FIG. 6.

FIG. 8 is a schematic representation of the expansion device employed according to a preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The apparatus according to the present invention is designated generally as numeral 10 in FIG. 1. A preferred manner of creating the hydraulic head necessary to accomplish the objectives of the present invention is the utilization of a well indicated generally as 11, of a prescribed depth which, of course, would vary according to the pressure needed for the particular chemical reactions contemplated. Well 11 consists of a bore 12 into which is fitted a well casing 13. Concentric of casing 13 is a liner 14 of smaller diameter than casing 13. Concentric of and spaced within liner 14 is a heat energy or steam line 15 which, as shown in FIG. 5, is preferably encased by an insulating sleeve 16 through the majority of its length so that the heat energy in the form of steam will not be lost to the surrounding environment. Steam line 15 is therefore utilized to provide the heat energy necessary for the chemical reactions desired. However, it should be evident that other forms of heat energy, such as electricity, might well replace the steam energy in certain installations.

The bottom of the well 11 is best shown in FIG. 5 as being closed off to the strata by a cement or grout 18, which can hold the casing 13 in place. Slidably received within casing 13 is a circular base member 19 having an outer annular flange 20 and resting on the grout 18. Base member 19 further provides an additional barrier to prevent significant contact of the fluid medium with the strata or with the grout system 18. Flange 20 of base 19 is provided basically for strength, base 19 being designed of a material having high corrosive and erosive resistance. Base 19 further has a center upright leg 21 which provdes a seat for the bottom of steam line 15, steam line 15 being preferably welded thereto. Welded to base leg 21 is a spider 22 which has a plurality of radial branches providing outer shoulders 23 on which rest an outwardly tapered annular extension 24 of the bottom of liner 14. Extension 24 not only provides a mating face to rest on shoulders 23, but also serves to form a venturi zone to ease pressure losses at the reverse flow point as will hereinafter become evident.

Interiorly fastened to the liner 14 at the upper end of extension 24 is an annular ring 25 which is mounted, as shown in FIG. 5, in a plane transverse to that of the liner 14. Similarly, a smaller ring 26 is attached exteriorly of steam line 15, creating a restricted orifice 28. Rings 25 and 26 are shaped in cross-section like a parallelogram having no right angles therein. This is done so that even though the rings do not rest in a plane perpendicular to the liner 14, their surfaces 27 are nevertheless parallel to the liner. Orifice 28 is adjustable in size by mere rotation of liner 14. As shown, orifice 28 would be at its smallest extent; however, rotation of liner 14 by 180.degree. to the chain line position would open orifice 28 to its greatest extent. Orifice 28 can thus be adjusted to provide the desired amount of mixing action in the effluent passing through spider 22 upwardly into liner 14.

Steam line 15 is provided with a plurality of discharge jets 29 which direct steam toward orifice 28. It is at approximately this area where the most rapid chemical reaction will take place, it being the area of greatest pressure and temperature in the system.

The assembly of these various components into well 11 should now be evident. Casing 13 is first set in grout 18 and the steam line is lowered with the base 19 attached thereto. Liner 14 is then lowered and extension 24 placed on shoulders 23 of spider 22. Finally an additionally grouting material 30 is packed around casing 13 within well bore 12. Grout 30 can be dry sand or powdered cement or a cement slurry mixture with additives for thermal stability and insulation purposes and is utilized to equalize the pressure inside and outside the casing. Grout 30 thus protects the casing from the eventual pressures of the strata and also acts as an insulation material.

Above ground level, liner 14 is shown extending through the top elbow of casing 13; therefore, a seal at 31 must be provided. Similarly, another seal at 32 is required where steam line 15 extends through the top elbow of liner 14. The seals 31 and 32 may be of a conventional construction. Steam line 15 then continues to a conventional steam generator (not shown).

In the discussion of the preferred embodiment, the process of devulcanizing rubber may be used as representative of many other treatments which system 10 is capable of accomplishing. In this instance then, the discarded rubber to be treated is ground up into small bits and placed in a carrying medium which may be water or which in the devulcanization of rubber example may be a zinc chloride brine or caustic soda. In this manner, the conveying medium would aid the reaction with its catylitic effect. As will hereinafter become more evident, when a conveying medium other than water is utilized, it is possible and often desirable to provide in line 15 the vapor of the conveying medium as the heat energy. Of course, when water is the conveying medium, steam would be the most efficient form of heat energy.

The mixture of ground rubber and water or catylitic brine is supplied to an influent tank or line 33 as shown in FIGS. 1 and 2. Referring generally to FIGS. 2 and 3, provisions have been made so that the influent rubber in suspension coming from line 33 may by-pass the entire system. This is shown in FIG. 2 as an open by-pass channel 34 having control gates 35 and 36 at the inlet and outlet thereof respectively. While being shown as open channels, it is evident that any medium, such as a pipe, would be sufficient. Thus in the schematic FIG. 3, a simple by-pass line is shown having a normally closed valve 38. This by-pass system could be utilized, for example, either in times of emergency, as in system overflow or breakdown, or in other situations where by-pass might be desirable.

If by-passing is not desired, the influent will then pass through gate 39 of FIG. 2 (normally open valve 40 of FIG. 3), and through a screening device 41. Screen 41 assures that no oversize particles of rubber reach the hydraulic column itself. Another normally open valve 42 may be provided after screen 41. At this point it has been found desirable to provide a classifier 43 (FIG. 3) which acts to segregate materials by specific gravity to eliminate overly dense or large undesirable particles which may have been passed the sizing test afforded by screen 41.

In the embodiment of FIG. 1, an above-the-ground lateral extension 44 of casing 13 is provided through partition walls 45. Casing extension 44 is connected to a downturned pipe 46 which serves in a siphon-like manner to pick up the influent rubber in suspension. A classifier, similar to that discussed with reference to FIG. 3, is thus provided at the mouth 47 of pipe 46. Mouth 47 acts like a siphon and will pick up only those particles which are light enough, thus eliminating overly dense materials. Further provided therein is a bar 48 which acts not only to help stabilize the system, as will hereinafter be discussed, but it also duplicates the conditions found in the well 11 compensating by velocity selection design for the change in viscosity of the carrying fluid at the reverse flow point in the hydraulic column and thus assures that oversize and overweight particles will not clog the system. Bar 48 also provides a means for regulating the uptake force of mouth 47. A large bar will increase the uptake suction velocity at mouth 47, due to the decrease in the relative area of mouth 47.

The influent rubber in suspension should now be ready to enter into the hydraulic column, or what has been previously referred to generally as well 11. The influent flows by gravity down in the area defined by the inside of casing 13 and the outside of liner 14. Preferably, there is provided in this passage a plurality of influent probes 49 shown in FIG. 1, which are, in effect, long adjustable pipes or tubular members of small diameter which can be used to take off a sample of the influent at any desired depth, or, more importantly, can be used to add catalytic chemicals at the exact pressure and temperature condition needed. Thus in the present instance, it would be desirable to add zinc chloride or caustic soda to the influent rubber in suspension. These substances will, at the right temperature and pressure, tend to break the sulfur bond associated with vulcanization. It should be noted that while these substances may be added in tank 33, classifier 43, or at any point of influent travel, the probes provide for introduction of the chemical substances under the most effective temperature and pressure conditions.

As previously alluded to, well 11 may be designed both in depth and in cross-sectional area according to the use for which it is intended. For whatever use, however, the peak temperature and pressure conditions will be found at the bottom in the area of orifice 28 and jets 29. Referring to FIG. 5, the influent under hydraulic column pressure is directed by shoulder 24 and base 19 up through spider 22 toward orifice 28 whereupon it is instantly contacted by the extreme heat of the steam from jets 29. This heat and pressure combined with the injected chemical agents causes a substantial devulcanization of the rubber in suspension.

Since the devulcanization of rubber must be accomplished in the absence or near absence of air, care must be taken to assure that very little air is entrained in the influent supply. Otherwise, the heat and pressure conditions achieved by this system would cause combustion, burning the rubber and leaving no usable end product. Thus, the influent must be oxygen-deficient, that is, not have enough oxygen to cause substantial combustion. By keeping the reactoin zone free of extraneous oxygen, that is, oxygen added in the process, this result can be achieved.

The treated material, now being heated and lighter, will be forced up the area between liner 14 and steam line 15 as the sole result of the change in density of the material. The air-lift characteristic of the prior art is not necessary (nor desirable, as described above). Thus, a continuous movement of the system is provided.

It should be evident that the substantially warmer effluent treated rubber in suspension will tend to heat the influent non-treated rubber in suspension via conduction through the walls of liner 14. For these purposes, liner 14 should be relatively thin or made of a material which will readily transfer heat. Further, if the liner is sufficiently thin, it may be flexed by flow reversal to crack off adhering brittle materials.

Thus after the initial "start-up" conditions, the essentially cold influent will be warmed throughout its downward journey by the relatively hot effluent which is moving upward. As will hereinafter be more specifically explained, and as now should be apparent, most of the heat energy provided by the steam is thus conserved within the system. Further, the high pressure is constantly maintained at no extra cost due to the hydraulic column.

By the time the effluent reaches the top of well 11 it will be substantially cooled having passed much of its heat to the oncoming influent. However, a recirculation channel 50 is preferably provided at this point, should it be desired to capture whatever heat remains in the effluent treated rubber solution or should it be desirable to provide a means which would permit a reversal in flow of the entire system. As shown in FIG. 2, the recirculation system may be an open channel with a control gate 51 and separating device 52, or as schematically shown in FIG. 3, it may be a piping system having a normally open valve 53 which allows the material to enter a separator 54. Both separators 52 or 54 are designed to take off the devulcanized rubber and allow the warm carrying medium and any remaining vulcanized rubber to continue back through the system again. This is accomplished since devulcanized rubber tends to be lighter than vulcanized rubber, the former thus tending to move toward the top of the separator to be taken off there, and the latter gravitating to the bottom to be fed with the warm water through a variable valve 55 and back to classifier 42 for further treatment.

Should recirculation not be desired, either valve 53 or 55 could be closed and, in the channel form of FIG. 2, outlet control gate 56 be opened, or in the schematic form of FIG. 3, either or both of valves 58 opened. This would open the effluent to a screen or series of filters 59 which would act like separator 54 in selecting the desired product and emitting it through either or both of valves 60. Note that two filters are provided so that one can be used while the other is being cleaned of the materials via backwash valves 61. Also provided at the downturned end of liner 14 is an adjustable sleeve member 58 (FIG. 1) which regulates the back pressure in liner 14. As sleeve 57 makes liner 14 larger (and thus closer to the bottom of the tank shown), more back pressure in liner 14 is provided, should it be desirable.

Referring generally to FIG. 8, it has been determined that due to the high heat involved in the system, compensation should be made for pipe expansion. Shown in FIG. 8 is one example being applied to the steam line. There, the top of steam line 15 has conventional pipe elbow joint 62 which holds articulating arm 63. The other end of arm 63 is connected by another joint 64, arm 63 and steam line 15 thus being connected to the steam generator 65. As steam line 15 heats up and expands, arm 63 moves from the chain line position to the full line position of FIG. 8 by rotation at joints 62 and 64. By varying the length of arm 63, most any pipe expansion can be accounted for. Since arm 63 must be quite long in certain instances, springs 66 are provided to alleviate any binding stresses at joints 62 and 64 due to the weight of arm 63. One alternative method of compensating from the pipe expansion would be to provide conventional expansion means between each length of pipe in the steam line itself. By utilizing this concept, each joint would have to account for a small fraction of total pipe expansion. Another alternative would be to provide a "hanging" liner 14, that is, suspend the cold liner above the shoulder 23 of spider 22 and allow it to "grow" downward when heated. The hanging liner, as well as seated liner for that matter, would be readily adaptable to facile raising and lowering which would aid in maintaining the liner free of undesirable materials.

Also, as seen in FIG. 6 and 7, each pipe union of liner 14 has a system of stabilizers 68. The stabilizers consist of spirally curved lengths of rod which are welded, as at 69, at each pipe junction, and which rest against either the casing at 70 or steam line at 71. In effect these rods are spring loaded in that their force against the casing and steam line tend to keep the whole piping system centered on installation and during use. Further, these stabilizers will not only tend to dampen vibrations which might occur, but also provide a plurality of obstructions in the path of both the influent and effluent, which obstructions tend to mix the flow and keep the pipes clean. Stabilizers are also provided at the mouth 47 of pipe 46 for similar purposes.

Being obstructions to the flow, that is, being placed angularly to the flow of the material, it is evident that the stabilizers 68 can be designed to perform the additional function of turning or rotating the liner by a paddle wheel effect. This rotation would not only deter adherence of materials to the liner and break liner surface film and thereby improve heat transfer characteristics, but when in the path of the effluent, stabilizers also favorably utilize the excess head that may be present therein, as will hereinafter be described.

Having now discussed the system 10 in general terms with respect to the process of devulcanizing rubber, it would be best to define various parameters of such a devulcanization system. While devulcanization will occur at 350.degree. F. under a pressure of 600 psi, it has been determined that a more rapid devulcanization will occur at a temperature of 500.degree. F. under a pressure of 1,000 psi. It would thus be desirable to obtain these conditions at the bottom of the hydraulic column.

In order to achieve a pressure of 1,000 psi, a well of approximately 2,300 feet would be required. A system of this depth is calculated to handle 5,000 pounds of rubber dispersed in 50,000 pounds of water each hour with an outer casing of at least 9 inch diameter, a liner of about 6 inch diameter, and steam line of about 3 inch diameter.

While the securing of the required pressure is thus only a function of depth, the heating requirements are somewhat more complex. For example, heat gains are derived from the steam itself, from pipe friction, and from exothermic reactions. Heat losses involved are those to the strata, those due to condensation in the steam feed line and those which account for the terminal temperature difference. Finally, heat transfers from effluent to influent must be considered.

The losses attributed to the strata are considered first. Of course, the well site should be a comparatively dry one, for if not, the heat would be quite readily carried off by any present moisture. Assuming relatively dry strata, the heat losses to the strata may be described as the instantaneous heating of an infinitely thick wall. The heat losses are found to be inversely proportional to the square root of time (in hours) so that while never reaching zero, it is evident that the losses become minimal after a short period of time. In fact, it is only during "start-up" and shortly thereafter that the losses are appreciable. After that, the heated strata actually acts like an insulator. If it were desired to minimize initial losses to the strata, an adequate insulating material could be packed around the outer casing in place of the grout material. However, one would have to weigh the cost of this insulation versus the cost of providing extra steam at the initial stages of the process. Due to the relative economic ease of steam production, it would seem that the latter choice would be preferred.

In the example under discussion, it has been calculated that the losses after 1 year would be approximately 50,000 BTU per hour; after 2 years 33,000 BTU per hour; and after 3 years 26,000 BTU per hour. In steam output, this would mean a consumption, at the 1 year point, of about 77 pounds per hour.

Continuing the example, assuming heat losses after 1 year (since it is recognized the initial heat losses would be greater and those later would be lesser), it is found that if the influent temperature is 195.degree. F. (obtained from recirculating warm effluent), and if the peak temperature condition is 500.degree. F., the effluent will reach the top of the well at about 211.degree. F., thus cooling from 500.degree. F. to 211.degree. F. The 289.degree. F. difference is, of course, largely transferred from the effluent to the influent through the liner, which in terms of BTU's amounts to 905,000 BTU/.degree.F-Hour. Thus there is a terminal temperature difference of about 16.degree. F., which difference, when expressed in terms of steam consumption, means about 1,270 pounds of steam per hour.

The loss due to condensation in the steam line has been calculated at about 91,500 BTU per hour which means about 141 pounds of steam per hour. Note that in this regard, it has been mentioned that the steam line should be insulated. The reason for this is to prevent over-condensation as the steam travels down the line, and to prevent a heat loss from the steam line to the effluent. The net result is that the maximum steam can be provided at the maximum depth with only 141 pounds of steam lost each hour to condensation.

The total losses then (strata: 77; steam condensation: 141; and terminal temperature difference: 1,270) amount to 1,488 pounds of steam per hour needed after 1 year's use. A steam generator with an output of 3,000 pounds per hour would thus be adequate, in this example, for "start-up" and all subsequent conditions.

It has been found that when considering heating requirements of the above described magnitudes, both of the heat gains alluded to above become negligible. For example, the heat gain from friction would amount to about 700 BTU/hour, or about a savings of 1 pound of steam per hour. Thus, while prior art devices utilize the heat from the reaction to maintain the combustion of the fortified sewage material, these heat gains are so insignificant to the present device that they are deemed negligible.

The friction loss does play an important role, however, as a deterent to the thermal head which provides the motive force in the system. The differential thermal head, that is, the motive force in this example, has been calculated at approximately 10 psi. However, the total friction losses amount to about 10.5 psi. Therefore, in this particular example, either a static head would have to be created, i.e., raise the level of the influent, or a very small amount of steam be added over the saturation requirements. In the latter situation, the addition of a very small amount of steam significantly increases the head. This is due to the fact that any steam injected over saturation will remain as steam in the effluent, and thus substantially lighten the effluent and cause a greater flow therein. Therefore it is evident that the amount of steam controls the flow rate in the system. In the example above, the total flow time, as regulated by the steam, was only 59 minutes.

The overall temperature-pressure conditions in the system just described can be best seen in the graphic representations of FIG. 4. The screen device 41 causes a slight pressure drop due to the slight resistance which it presents to the influent. A representation pressure drop of 1 psi is shown. Similarly, a small pressure drop occurs in the classifier. Then as the material passes into the casing of the well, the maximum point is reached. Of course, at this point the pressure will fluctuate somewhat radically due to the fluid flow around the reversal point and through the orifice. Then, as the material moves up the liner, the pressure decreases until the material is expelled at a pressure, which, of course, varies as a function of the thermal head involved. In the example given above, it is assumed that enough extra steam has been added to give the 30 psi output pressure shown in FIG. 4. Then the pressure drops again at the filter area before being ejected.

The temperature at these various points is shown on the lower graph of FIG. 4. The influent temperature remains fairly constant after 1 year, except for the small increase due to the recirculation input, until reaching the hydraulic column. There as it passes by the warm liner, it gains heat progressively until it reaches the bottom when the temperature is "bumped" up by the steam injection. Then the effluent loses its heat to the influent until it reaches the top of the column. There it is taken off at a slightly higher temperature (in this example 16.degree. F.) than the influent. This warmer effluent can either be merely ejected from the system and the heat lost to the atmosphere, or it can be recirculated to mix with the cooler influent.

TREATMENT OF SEWAGE

The use of the above-described apparatus in treating sewage is important since raw untreated sewage, obtained naturally from cities and the like and unfortified by combustible refuse or oxygen can contain many materials, most of which are undesirable and most of which can be purified by the use of a high pressure and temperature environment. Further, raw sewage lends itself to this apparatus since it already consists of a great deal of water which will act as its carrying medium, and since it must be handled efficiently in large volumes.

While there may be entrained oxygen and/or combustible material present in naturally occurring sewage, an advantage of the present process, particularly when treating sewage, is that extraneous oxygen and refuse is not present in the reaction zone. That is, the present process does not require the affirmative step of adding oxygen or refuse extraneous to that small amount which may be inherently present in the material as it is provided to the hydraulic column 10. Of course, as previously described, processes which do require such procedures are at a decided disadvantage. However, denying oxygen to the reaction zone having a minimum of combustible refuse present does not allow the reaction to be taken over by the wet combustion process. Naturally occurring unaugmented sewage is simply too oxygen-deficient for such to occur.

The treatment of sewage, nevertheless, is very much like the devulcanization of rubber, however, many of the steps become more critical and others may be eliminated. Initially, raw sewage from a community would be directed to the influent tank 33. The screening device 41 and bar 48 become important in this instance since the size of the particles in sewage cannot be controlled as readily as, for example, in the devulcanization of rubber.

The by-pass provisions are also helpful in the sewage situation, for example, to shut down the system for cleaning. Just as before, if not by-passed, the sewage would pass through the classifier 43 and onto the hydraulic column. Probes 49, which as discussed above, can be positioned at any height within the influent or effluent, are quite effective as samplers in the process of treating sewage. However, in general, since no chemical is ordinarily added in this process, the step of adding a catalyst may be eliminated in this instance. But, it may be necessary, for example in a community having vast industrial wastes in its sewage, for certain chemicals to be added to aid in the purification. Probes 49 are thus useful in this situation. A probe entering the cooler zones of the effluent may be utilized to introduce a refrigerant compressed gas to be cooled and condensed by direct contact with the fluid. Upon throttled discharge at control 57, the refrigerant would boil and extract heat from or after-cool the effluent. The gas could then be recovered by separation for recompression and recycle.

When peak temperature and pressure conditions occur (at the bottom of the well), the breakdown of the various undesirable materials, particularly those materials in suspension and colloidal dispersion, occurs. This system is advantageous in that except for the rough initial screening, the entire influent is treated chemically and physically by subjection to peak process conditions which are most efficiently over 1,800 psi and 635.degree. F. The time, temperature and pressure duration is intended to provide substantial hydrolysis of various fatty acids; sterilize pathogenic material; decompose meat proteins; pyrolize materials such as hydrocarbons; hydrogenize or carbonize cellulose, and others.

Since the natural environment of sewage is the liquid carrying medium, it would not be at all mandatory that the recirculation channel 50 be used. However, such a channel would be useful during a starting "warm-up" period and during periods of low sewage flow rates. Normally, however, the sewage effluent would usually pass to filters 59 and then into some natural water source such as a river or lake. Should some of the objectionable matter remain, however, the recirculation system could be utilized to return the effluent to recirculate through the system.

The parameters of the sewage treating system are similar to those in the devulcanizing system except that since a desirable peak pressure in 1,800 psi and temperature is 635.degree. F., a substantially deeper well of about 4,600 feet is needed. Further, a much larger diameter well is needed to handle greater volumes. For example, the standard treatment plant of the Public Health Service, serving a town of a 5,000 population, requires that 500,000 gallons of sewage be treated each day. To treat this volume, a casing of approximately 14 inches, liner of 10 inches, and steam line of 4 inches would be necessary.

Just as in the devulcanization of rubber, the heat losses, gains, and transfers must be considered. Assuming relatively dry strata, the heat lost to the strata after 1 year in this example would be approximately 115,000 BTU per hour, which would mean a steam consumption of 250 pounds per hour lost to the strata.

Without recirculation, the average influent temperature of sewage is about 50.degree. F. Note that this is substantially less than the 195.degree. F. in the influent rubber situation. After the 50.degree. F. sewage reaches the 635.degree. F. peak condition, it will cool until it exists at about 84.degree. F. The 551.degree. F. temperature difference is, of course, transferred directly to the influent. Thus there is a terminal temperature difference of about 34.degree. F., which difference translated into steam consumption means about 13,150 pounds of steam per hour. This steam consumption could obviously be reduced by increasing the heat transfer area of the liner if desired as by providing fins as would be well known to one having ordinary skill in the art.

The additional heat or power loss due to condensation in the steam line has been calculated at about 349,000 BTU per hour or about 754 pounds of steam per hour.

The total losses, or the energy consumed, for this example then amount to 14,152 pounds of steam per hour. Again the heat gained from friction and the various exothermic reactions involved can be considered negligible considering the sizable amount of heat needed in this process.

The friction loss, however, would have an important effect on the thermal head created by the terminal temperature difference which provides the motive force of the system. Disregarding the friction loss, the thermal head would be about 87.2 feet considering the relative influent and effluent densities. However, the friction of the effluent going up the well reduces that head by an equivalent of 41.4 feet thus leaving a remaining head of 45.8 feet. As previously described, through the advantageous use of the stabilizers 68, much of the force of this thermal head can be used to rotate the liner and promote cleaning, and heat transfer, and is generally a source of mechanical energy. Nevertheless, due to the more drastic terminal temperature difference in this example, a much larger motive force is created and even though the well is twice as deep, the flow time is only 80 minutes.

It should now be evident that the apparatus and method herein can be adapted for any desired use by a mere change in system parameters and possibly slight changes in chemical additives. This system can be utilized to effect an unlimited number of chemical processes which are aided by high pressure. As examples, the chemical reaction known as pyrolysis (the destructive distillation of organic material in the absence of air) is one of the major chemical reactions which takes place in the purification of sewage and can be maintained at minimum temperature and pressure conditions of 550.degree. F. and 1,000 psi; alkylation (the replacement of a hydrogen atom with an alkyl group in an organic compound) will take place at a temperature of at least 266.degree. F. and a pressure of at leat 200 psi; hydrolysis (combination of greases and the like with water to normally form an alcohol and acid) will take place at a temperature of at least 480.degree. F. and a pressure of 600 psi; and hydrogenation (the addition of hydrogen to the molecule of an unsaturated organic compound) will take place at a temperature of at least 630.degree. F. and a pressure of 2,000 psi. In short, any form of chemical reaction in an oxygen deficient material can be promoted and it is contemplated that general water treatment, extractions of oil from sands or shales, reduction of metallic ores and general molecular degeneration of any material can be performed and accelerated. As previously described, however, not all of these processes would necessarily utilize water as a conveying medium or steam as the heat energy.

What has been described herein is a hydraulic activation device including those features which render the device satisfactorily operable. However, certain devices which would be known to those skilled in the art, such as chamber overflows, cleaning sumps, automatic level controls, process performance monitoring, irregularity alarms, cooling towers, gas separations, safety valves, corrosion protection and other engineering devices have not been described.

It can thus be seen that the apparatus and method disclosed herein carry out the aforementioned objectives and otherwise improve the high pressure chemical reactor art.

Claims

I claim:

1. A method for treating a continuously flowing sewage material comprising the steps of, feeding the sewage material into the top of a hydraulic influent column, conducting said material from the bottom of said influent column into the bottom of a separate hydraulic effluent column, continuously supplying heat energy to the material near the bottom of one of said columns at the reaction zone to promote chemical reactions and decrease the specific gravity of the material, limiting combustion of the material by restricting the process to oxygen present in the material, whereby the pressure at the bottom of said influent column causes the heated material to rise in said effluent column, and removing the material from the top of said effluent column.

2. The method of claim 1, in which the rising effluent column transfers heat to the descending influent column.

3. A method for treating an oxygen-deficient sewage material comprising the steps of, continuously feeding the material into the top of a hydraulic influent column; conducting the material from the bottom of said influent column into the bottom of a separate hydraulic effluent column; continuously supplying heat energy to the material near the bottom of one of said columns at the area of greatest temperature and pressure to promote chemical reactions to decrease the specific gravity of the material, and to provide a pressure differential between the material in said influent column and the material in said effluent column, the pressure differential provided by the heat being the sole cause by which the material rises in said effluent column; limiting combustion of the material by restricting the process to oxygen present in the material; and continuously removing the material from the top of said effluent column.

4. In a process of treating raw sewage material including the steps of feeding the sewage material into the top of a hydraulic influent column, transferring said material from the bottom of said influent column to the bottom of a separate hydraulic effluent column, and removing the material from the top of said effluent column, the improvement comprising the additional steps of supplying heat energy to the material near the bottom of one of the columns so that the specific gravity of the sewage material will decrease and the material will rise in the effluent column, and limiting combustion of the material by restricting the process to oxygen present in the sewage material.

5. A process according to claim 4, wherein said step of heating the material is done while restricting the process to combustible material present in the sewage material.